祁连山区降水的大气特征分析  

Analysis on Atmospheric Characteristic of Precipitation in Qilian Mountain

作　　者：马学谦[1] 孙安平[2] 

机构地区：[1]青海省人工影响天气办公室,青海西宁810001 [2]青海省气象局,青海西宁810001

出　　处：《高原气象》2011年第5期1392-1398,共7页Plateau Meteorology

基　　金：国家自然科学基金项目(40533015)资助

摘　　要：利用祁连野外试验站观测资料,引入客观反映高空大气云和降水的表示方法,分析了祁连山区降水的大气特征。结果表明,高层冷云和低层暖云是祁连山区形成降水的主要云系,高层冷云由天气尺度系统决定,而低层暖云则由地形阻挡和加热等作用形成。在不同的天气系统下,地形对降水的作用不同。在西南气流影响下易形成谷风环流,从而增强降水;在西北风、平直西风等气流影响下易形成山风环流,将水汽从谷底向中高空输送,但受主导气流抑制易形成浅薄的降水云层。夏季山顶附近温度在0℃以上,对应明显的湿区或饱和区,云以水云为主。此外,CAPI能够客观地反映高空云和降水出现的位置和基本特征;其随高度的变化趋势与地面降水随时间的变化趋势基本一致。Using the observated data of Qilian field experiment station and the introduction method of an objective reflection of upper atmospheric cloud and precipitation,the atmospheric characteristic of precipitation in the Qilian mountain is analyzed.The result shows that the cold cloud in upper level and warm cloud in lower level are to form main cloud systems of precipitation in the Qilian mountain,and the cold cloud in upper level depends on the weather system scale,but the warm cloud in lower level is formed by the terrain blocking and surface heating.In the different weather systems,the role of topography on precipitation is different.It is easy to form valley wind circulation to enhance precipitation under the influence of southwest air flow,and to form down valley wind circulation under the influence of the northwest and straight west air flow,the water vapor is transported from valley to mid-and upper-levels,but which is inhibited main leading air flow to form shallow precipitation cloud.The temperature above 0 ℃ is corresponding to the obvious wet and saturated zone near mountain top in summer,the cloud take the water cloud as main.In addition,CAPI can objectively reflect the upper-level cloud and position of precipitation occurrence and its basic characteristic,and its change trend with height is consistent to the change of surface precipitation with time.

关 键 词：祁连山区 云和降水指数 地形云 

分 类 号：P426.611[天文地球—大气科学及气象学]